97 Accord Overheating/ Thermostat Replacement
 

Hey guys,
So my girlfriend has a 97 Accord she bought recently. It runs fine but we were having to put water in the radiator about once a week and am not sure why. Its now getting warmer outside so i am having to fill it about every other day so it does not overheat. I dont know much about cars but someone told us if it starts to overheat to rev the engine a little, which works perfect since it only starts to overheat when you take your foot of the gas. We had her dad change out the thermostat on it to see if that was the problem and he noticed after replacing it that the bottome hose that goes to the back of the engine is staying cool and the top hose is hot. Can anyone tell me why?

I also took a picture to show some other hoses that are really hot which are pointed at with the black arrow. Should those be hot? Her dad also said that it shuld bleed out where the blue arrow points to, but when he opens it nothing comes out. And the red arrow points to the hose that stays cool.

http://i41.tinypic.com/11jlk3t.jpg

Re: 97 Accord Overheating/ Thermostat Replacement
 

Make sure your fan switch is working properly, (by the thermostat) if you jump it, your fan should start, if not something else is wrong like your fan relay. One of my F22 have had a microscopic crack in the iron sleeve before and require water just like you described; compression test to find out. Also if your temperature nob is turn to full red and one of the hose is cool then you may have a clogged or leaking heater core or your valve is malfunctioning. (the cable to the water valve slips easily so look underneath your dash where 1 screw hold it)

The hose where the red arrow is cooler than the top radiator hose until the thermostat opens.

To bleed the system. run vehicle until operating temperature or close to it and open bleeder valve ( near the goose neck)

Re: 97 Accord Overheating/ Thermostat Replacement
 

You may have air in the system thats not purged. From the blue arrow is the bleed valve, its possible it has clogged, you can try to use a paperclip or toothpick and poke it through. Its happened on a few of my cars. The red arrow is your radiator hose and if the thermostat was opening both those hoses would be hot (both radiator hoses that is). Yes the black arrow hoses should be hot. If you have to add coolant its either leaking or burning. I'm going to guess leaking and to couple that with having to rev it to cool it it may be your water pump on the way out. When was the last time she had that changed?

Re: 97 Accord Overheating/ Thermostat Replacement
 

I read online it could also have air in it so we let the car run for 15 minutes with the radiator cap off and we squeezed both hoses, there were some small air bubbles coming out during the 15 minutes but im not sure if thats normal or not. (i dont know much about cars) and during that 15 minutes the bottom hose never got hot but im assuming the thermostat opened because the fan was on the whole time. How would I know if its leaking or burning? And we actually dont know if the water pump has been replaced she bought the car a few months ago and cannot get ahold of the guy who she got it from.

Re: 97 Accord Overheating/ Thermostat Replacement
 

I know the fan works because it turns on a lot, pretty much everytime i turn the car off the fan runs for a few minutes afterwards. How do you do a compression test and where is the iron sleeve? When we try to bleed the system the car is warmed up and hot we had it running for a while and the fan was on while we were bleeding it but nothing comes out, we took the screw out and cleaned it to make sure theres nothing clogging it and theres still nothing coming out. BTW her dad said when he changed the thermostat the old one was covered in something thick. Im not sure if that helps.

Re: 97 Accord Overheating/ Thermostat Replacement
 

You need a pressure gauge to screw into into the spark plug hole to do a compression test. (at local parts store); turn over and the first couple of hits should be around 90-120psi, continuing to hold will give you maximum psi.(check your service manual for specs) but if you get the pre-mention values you should be ok. The iron sleeve is the lining of your cylinder wall. Also that gunk on the old thermostat is also in your cooling system (pathway and cavities), flush or clean immediately! If your not sure when the last time your timming belt and water pump has been replace I would advise to do so as HondaPartsHero has mention.

Re: 97 Accord Overheating/ Thermostat Replacement
 

regaurding the black arrow, those are matal lines. one has coolant but since they are metal thay will get warmer than regular hoses. maybe about the same temp as the lower hose should get. o to autozone and rent/borrow their block tester and compression gauge tools. cost you like 60 bucks. refunded in full when you return them. the block tester will tell you if you got a crack in the cylinder walls. or if you have a leaking head gasket. you wont know for sure which it is by that test alone. a shop will be needed for that. keep in mind that honda blocks usually dont crack that easily. although it has been know to occur. more than likely you have a blown head gasket because lots of regular people dont pay the extra money for a machine shop to do a valve job when replacing the head gasket. the old owner may have done this knowing he would be selling the car soon. in my shop we dont cut corners and the customer has to pay for it so that we do it right. check what your compression specs should be. the ones listed above (120) sound a little low. i would guess it should be more like 180 but i dont know for sure this second. i would have to look it up. the coolant system should be flushed and bled. we have had cars take as long as 20 minutes to bleed properly. sometimes air is trapped in the system and the coolant will flow from the bleeder valve and stop (letting out air) and then cycle a few times. this is from multiple air pockets. the gunky crap on the thermostat could mean that the coolant system has blockage from the previous owner not having the coolant system serviced regularly. try all that and hit us up for help if you need it

Re: 97 Accord Overheating/ Thermostat Replacement
 

178 psi normal compression, 135 psi minimal compression, no mare than 28 psi variation between any 2 cylinders.

Re: 97 Accord Overheating/ Thermostat Replacement
 

Hey guys thanks for your responses. So we tried to flush the radiator and noticed when we unhooked the top hose from the radiator while it was running there was hardly any water coming out. So we got the hose and started pushing water through the radiator and then the water started flowing through the top hose. It also started flowing a little bit more when you reved the engine a little. So from this we are guessing that it is most likely the water pump right?

Re: 97 Accord Overheating/ Thermostat Replacement
 

Ofcourse as the engine speed increase the water pump is going to move more water so in short, not a good idea to just go off of that. Water won't flow until the thermostate is open. (That's it job. To regulate a desired temperature) You need to remove the thermostat before trying to flush the system with a hose because the thermostat will be closed and restrict water flow in turn not a whole lot of water velocity. As I mention before that gunk that was on the old thermostat is in your water cavities. You will need all the force that you can get.

Re: 97 Accord Overheating/ Thermostat Replacement
 

like skracer said. remove the thermostat and just use a hose to flush your system. i had one guy come in who tried a pressure washer to flush his system...it broke the radiator. i have seen coolant get dry and get crusty inside coolant passages. i can only guess its from either not servicing the coolant system like people should and or from the vehicle sitting for a while and not being driven or at least started regularly

Re: 97 Accord Overheating/ Thermostat Replacement
 

Ok i will try that again. I was just not sure if running water through there without the thermostat could do any harm (like i said i dont know much about these things). I will post results soon. Thanks.

Re: 97 Accord Overheating/ Thermostat Replacement
 

Ok so I tried it again without the thermostat this time and the water came out the top hose fine. So does this mean it is the water pump?

Re: 97 Accord Overheating/ Thermostat Replacement
 

well i would go and get a new radiator its like 100 and new hoses and make sure the coolant had the right 50/50 mix and if those things dont work go get a head gasket fix stuff i think it would be best to do all these at the same time
this fix runs around 200 i just replaces the hole collent system on my 92
how many miles does the car have

Re: 97 Accord Overheating/ Thermostat Replacement
 

take your radiator out and see if it holds water. you need to pressurize it too. a think 13 pounds. or have your radiator tested at a radiator shop. might save you a few bucks

Re: 97 Accord Overheating/ Thermostat Replacement
 

Hello..ok i bought a jdm f22b sohc vtec to replace with my f22b2 in my 96 accord lx auto...i was told that i had to change out the oil pumps because of the crank postion sensor in the 96 n up accords, so i had the pumps changed, i also bought the correct ecu that i have to use, but im havin trouble finding out what distributor to use. I bought a 96 accord ex distributor but the plug dont match the engine harness out of my old motor because it has an external coil and the one i bought has an internal coil...so my question is do i need an accord ex engine harness? Is there anything else im missing to complete this engine swap? I want to keep everything obd2

Re: 97 Accord Overheating/ Thermostat Replacement
 

ummm i think this is in the wrong place. i think a new thread should be started. what do you guys think? or am missing something